Blackstar HT Drive - finer points ?

[Fusionista]

The Marshall 50 has headroom in comparison with the PP18 so you are pushing a cleanish signal into OD rather than distorting an already overdriven pre-amp valve. The tone target is - as always - that creaminess and crunch with the touch of compression that come as an amp power stage clips. What I understand most OD pedals to be doing is pushing the pre-amp stage to give you a similar effect at lower volumes. Generally I find it is not as satisfying because you don't get the harmonic complexity that you get from overloaded power valves (as well as the effect that sheer volume has on speakers, eardrums and indeed the brain). A lot of modern OD's do try to give some extra tonality, and depending on your guitar, the amp and your settings, sometimes it works well and sometimes not so well - hence the millions of opinions on the blogosphere - and the industry.

[ICBM]

At low volume neither amp is distorting though. The problem is EQ - the 18W circuit has none other than a single tone control which basically just rolls off treble. This makes it difficult to dial in a sound at low volume because the EQ curve is then wrong for how your ear perceives a quiet sound as opposed to a loud one - in particular, at low volume you need a lot more bass and a lot less mid to give "the same" type of sound as you get at higher volume. If you have a one-knob pedal (varieties of midrange, really) into a one-knob amp (same) you can't do that at low volume, and it sounds either boxy or harsh or a combination of the two.

A three-band EQ allows you to fix that, as well as most of the standard ones having an inherent natural mid cut anyway. The type of circuit used in most guitar amps is also quite crude and not at all 'hi-fi', and adds harmonic distortion and frequency-dependent phase shift, which also makes the sound more open and 'big'.

So to get a good 'big amp' sound at low volume, you need at least one three-band EQ somewhere in the chain... in my experience. The Blackstar pedals with it (the Dist and the Dual) also have a mid sweep control they call the "ISF", so you can fine-tune the mids even better.

[Fusionista]

Very interesting. And yet another avenue for GAS to develop...

[evilmags]

I use an HT Metal with a Blackstar Artisan 15 and it sounds awesome on either 5 or 15 Watt settings. Channel one on it is basically an overdrive, and it sounds ver nice and warm.

[Lustycourtier]

I had one of them pedals, had to much bass for my liking, was to thick even with a strat

This. Coupled with pots that move if you even look at them, and a switch that didnt always work first time it when straight back.